RATIS-1884. Fix retry cache warning condition (#915)

(cherry picked from commit 4e5443a)
apache · Sep 5, 2023 · a483bd4 · a483bd4
1 parent 1dc6c35
commit a483bd4
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diff --git a/ratis-docs/src/site/markdown/configurations.md b/ratis-docs/src/site/markdown/configurations.md
@@ -538,6 +538,8 @@ Note that `slowness.timeout` is use in two places:
 | **Description** | expire time of retry cache entry     |
 | **Type**        | TimeDuration                         |
 | **Default**     | 60s                                  |
+Note that we should set an expiration time longer than the total retry waiting duration of clients 
+in order to ensure exactly-once semantic.
 
 | **Property**    | `raft.server.retrycache.statistics.expire-time` |
 |:----------------|:------------------------------------------------|

diff --git a/ratis-server-api/src/main/java/org/apache/ratis/server/RaftServerConfigKeys.java b/ratis-server-api/src/main/java/org/apache/ratis/server/RaftServerConfigKeys.java
@@ -793,6 +793,7 @@ static void setSlownessTimeout(RaftProperties properties, TimeDuration expiryTim
   interface RetryCache {
     String PREFIX = RaftServerConfigKeys.PREFIX + ".retrycache";
 
+    /** We should set expiry time longer than total client retry to guarantee exactly-once semantic */
     String EXPIRY_TIME_KEY = PREFIX + ".expirytime";
     TimeDuration EXPIRY_TIME_DEFAULT = TimeDuration.valueOf(60, TimeUnit.SECONDS);
     static TimeDuration expiryTime(RaftProperties properties) {

diff --git a/ratis-server/src/main/java/org/apache/ratis/server/impl/RaftServerImpl.java b/ratis-server/src/main/java/org/apache/ratis/server/impl/RaftServerImpl.java
@@ -1777,7 +1777,7 @@ private CompletableFuture<Message> replyPendingRequest(
     // update the retry cache
     final CacheEntry cacheEntry = retryCache.getOrCreateEntry(invocationId);
     Preconditions.assertTrue(cacheEntry != null);
-    if (getInfo().isLeader() && !cacheEntry.isCompletedNormally()) {
+    if (getInfo().isLeader() && cacheEntry.isCompletedNormally()) {
       LOG.warn("{} retry cache entry of leader should be pending: {}", this, cacheEntry);
     }
     if (cacheEntry.isFailed()) {